Gargoyleosaurus ("gargoyle lizard") was an armouredankylosaur) which walked on four legs and had a stiff tail. It had a series of spikes running along each side of its body. Gargoyleosaurus was about 10 feet (3 m) long and was roughly 3.3 feet (1 m) tall to the top of the shoulder it may have weighed about a ton.

This dinosaur had a long, narrow beak with teeth on both the upper and lower inner surface (most other ankylosaurs have teeth on only the lower beak). This plant-eater had protective body armour on the upper surface of its body and tail (hollow bony oval plates).